ul {
  padding: 0;
  margin: 0;
  list-style: none;
}

.ul {

}

.ul::after {
  display: block;
  content: '';
  clear: both;
}

.drop,
.drag {
  float: left;
}

.drop {
  width: 30px;
  height: 200px;
}
.over {
  border: 1 dashed #ccc;
  background: #ffffbb;
}
.drag {
  width: 100px;
  height: 200px;
  border: 1px solid #ccc;
}